1. Field of the Invention
The present invention relates to an anti-rhodopsin monoclonal antibody useful for utilizing rhodopsin as a photosensor, an optical information recognition element, etc. and use thereof.
More particulalry, the present invention relates to an anti-rhodopsin monoclonal antibody which reacts with rhodopsin without inhibiting photochemical reaction of rhodopsin, an anti-rhodopsin monoclonal antibody which has different affinities to rhodopsin and metarhodopsin, a hybrid antibody which can concurrently recognize rhodopsin and a thin layer constituent molecule, a method for fixing or immobilizing rhodopsin using these antibodies, a process for preparing arhodopsin thin layer, a method for photochemical detection of the rhodopsin thin layer, and relates to the rhodopsin thin layer.
2. Related Art Statement
As substances which take part in information processing in vivo, there are known functional proteins such as acetylcholine receptor, rhodopsin, etc. If their functions are artificially exhibited using these functional proteins, it would be possible to provide extremely effective sensors or information processing elements. In order to obtain such sensors or elements, it is necessary to fix these proteins on a carrier or substrate without damaging the functions of proteins.
Rhodopsin is a visual pigment which is a sensor for recognizing optical information and a membrane protein widely distributed in vertebrate and invertebrate species, giving attention to its use as a material for photosensor or optical information recognition element. Rhodopsin consists of opsin protein and 11-cis-retinal. Upon exposure to light, cis-retinal turns to trans-retinal to form metarhodopsin. Color pigments associated with color sense undergoes a similar change. For example, octopus rhodopsin turns, upon exposure to a blue light, to a mixture of photoproducts, metarhodopsin and rhodopsin. In this case, the maximum absorption wavelength is shifted from 475 nm to 500 nm. When exposed to a red light of 580 nm or longer, rhodopsin can be regenerated from metarhodopsin and the maximum adsorption wavelength is reverted to 475 nm [Tsuda, Motoyuki; Biochemica et Biophysica Acta, 578, 372-380 (1979)]. That is, it is considered that in the case of octopus rhodopsin, the two states could be controlled by selecting either a red light or a blue light and octopus rhodopsin would be usable as a photosensor or an optical memory. Color pigments which participates in color sense also undergoes a photochemical reaction similar to-that of rhodopsin. Thus, attention has been focused on rhodopsin-like substances which take part in visual sense.
In order to utilize rhodopsin as a photosensor or an optical memory, it is necessary to immobilize rhodopsin. The Langmuir-Burget method (hereinafter abbreviated as LB method) is known to be a method for fixing protein to prepare a thin layer. It is reported that, for example, bovine rhodopsin is laminated onto a glass plate by the LB method and its photochemical reaction is spectrophotometrically determined [Korenbrat et al., J. Membrane Biol., Vol. 37, 235-263 (1977)]. That is, rhodopsin is incorporated into phosphatidyl choline membrane and spread over the surface of water; the spread layer is transferred to a glass plate to prepare a rhodopsin thin layer.
However, the known technique described above encounters problems that rhodopsin cannot be arranged or fixed in a specific direction, it is difficult to immobilize rhodopsin without damaging the function of rhodopsin, and that rhodopsin cannot be regularly arranged, photochemical reaction of the rhodopsin thin layer cannot be directly detected.
On the other hand, antibodies or monoclonal antibodies have been notably marked out only as probes for tissue distribution or functional analysis of protein but also as materials for fixing functional proteins. For immobilizing rhodopsin using antibodies, there is disclosed in Japanese Patent Application Laid-Open No. 63-111428 a method in which rhodopsin is incorporated into liposome consisting of hapten-bound phospholipid, and the liposome is two-dimensionally arranged on a substrate using an antibody specific to the phospholipid to immobilize rhodopsin thereby to construct a biological element capable of converting external optical information into various ions and chemical substances.
With respect to monoclonal antibodies against rhodopsin, antibodies against bovine, and rat and bacteriorhodopsins are constructed as shown below. C. J. Barnstable et al. constructed monoclonal antibodies capable of recognizing photoreceptor tissue, using the crude membrane component obtained from rat retinas as antigen and, analyzed the structure of the photoreceptor tissue using anti-bovine rhodopsin monoclonal antibodies in combination [J. of Neurocytology, 12, 785-803 (1983)]. D. MacKenzie et al. has also constructed monoclonal antibodies capable of recognizing the C-terminus of bovine rhodopsin and analyzed distribution and change of rhodopsin in visual cell disk membrane [Biochemistry, 23, 6544-6549 (1984)]. However, any anti-rhodopsin monoclonal antibody which is usable as a photosensor or an optical information recognition element, etc. has not been developed so far.